1. Field of the Invention
The present invention relates to an endoscope applicator and endoscope apparatus. More particularly, it relates to an endoscope applicator for use to insert an insert portion of an endoscope into a body cavity as well as to an endoscope apparatus which uses the applicator.
2. Description of the Related Art
When inserting an insert portion of an endoscope into a deep digestive tract such as a small intestine, it is difficult to insert the insert portion into the depth by simply pushing the insert portion because the force is not transmitted readily to the tip of the insert portion due to complicated bends in the intestinal tract. To deal with this situation, an endoscope apparatus has been proposed which inserts the insert portion of the endoscope into the body cavity by fitting an applicator called an overtube or sliding tube over the insert portion, guides the insert portion by the applicator, and thereby prevents excess bending and flexion of the insert portion (e.g., Japanese Patent Application Laid-open No. 10-248794). Incidentally the overtube is an applicator used in the small intestine while the sliding tube is an applicator used in the large intestine.
Also, it has been proposed to form a lubricant inlet at a base end portion of the conventional overtube, pour lubricant through the inlet into the base end portion of the overtube, and thereby improve slidability of the endoscope insert portion along the overtube, reducing the time required for endoscopic procedures. Water, a physiological salt solution, or the like is used as the lubricant.
Furthermore, known endoscope apparatus include double-balloon endoscope apparatus which have a first balloon at a tip portion of the endoscope insert portion and a second balloon at a tip of portion the applicator (e.g., Japanese Patent Application Laid-open Nos. 2001-340462 and 2002-301019).
With a double-balloon endoscope apparatus, the bent intestinal tract is sometimes contracted in a straightened state by inserting a predetermined length of the insert portion and applicator in the intestinal tract, inflating the two balloons, and pulling in the insert portion and applicator simultaneously with the two balloons placed in intimate contact with intestinal walls. Subsequently, the insert portion and applicator are pushed and pulled repeatedly to draw up the intestinal tract and put the insert portion in a desired site. In the pull-in operation, the physician grips the applicator made of an elastic member, thereby bringing it into intimate contact with the insert portion by elastic deformation, and pulls in the applicator, thereby pulling in the insert portion at the same time by means of frictional resistance between the applicator and insert portion (e.g., Japanese Patent Application Laid-open No. 10-248794).
When the inflated first balloon or second balloon comes into too intimate contact with, or adheres to, intestinal walls, if the physician pulls in (pull out) the insert portion and overtube forcibly, the intestinal walls may be damaged. In such a case, i.e., if the physician feels a strong pull-out resistance, conventionally he/she lowers the adhesive force by rotating the overtube or insert portion before resuming the pull-in operation.